l was wondering about what could be done to improve the performance and power. l have not done much beside add tints but l am considering installing a cold air intake which should add a little extra but is there anything else out there?

http://cobbtuning.com/categories/?id=2430
they sell good stuff.
you could upgrade the turbo and things but you start to push the limits of everyday reliability.

The best & least expensive thing to do is a free-flowing re-usable air filter and/or cold air intake, better exhaust system, change to synthetic oils, air up the tires to the maximum recommended, & if u have the money & time, dyno tune the car so that the ECU is optimized for u modifications. Beyond these recommendations, u r looking at HUGE amounts of money, starting at new suspension & all the way up to engine mods/rebuild & a sequential gear box. Start with the least expensive & descide what u really want to accomplish with the car & its' performance.

l would hold off on the intake, personally. Unless u really like the sound. They typically cost a LOT of money without making significant gains for the price. A ST l or K&N air filter for the stock housing will also increase airflow into the engine.

That car is turbocharged & one of the most popularly ''tuned'' engines available today. The best bang for the buck would be a full 3'' exhaust. This actually decreases some of the stress on ur turbo & engine with lower operating temperatures resulting from less back-pressure so close to the turbo. Upwards of 30 hp can be had from this change.

And also there is a lot of ECU mapping available for those engines also. Many operate on a stage system (Stage 1, Stage 2, etc.) that point out what hardware is required to safely use the tune (intercooler, injectors, etc). This is sometimes called an off-the-shelf tune. Getting a custom tune for ur car on a dyno for ur installed parts will yield the highest horsepower.

exhaust system, ECU, boostup those are basics
get a very good clutch and flywheel
better intercooler

if you're talking about budget tuning.

What a lot of people do not know is that turbocharge Subaru is have come with a factory cold air system for years now & they flow plenty for up to over 300hp at the wheels. l would skip that & as stated by others just get a turbo back & re flash or get a custom tune. It will amaze u how much power just that will give you. Also work on the suspension. l like to do suspension before power. It makes the car look good & handle better & that is important if u increase power.

Manual boost controller, turbo-back exhaust and a dyno tune.
Oh and more fuel. ;)

fuel injectors, headers, exhaust, turbo,